builtin/grep.c

   1 /*
   2  * Builtin "git grep"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "blob.h"
   8 #include "tree.h"
   9 #include "commit.h"
  10 #include "tag.h"
  11 #include "tree-walk.h"
  12 #include "builtin.h"
  13 #include "parse-options.h"
  14 #include "string-list.h"
  15 #include "run-command.h"
  16 #include "userdiff.h"
  17 #include "grep.h"
  18 #include "quote.h"
  19 #include "dir.h"
  20
  21 static char const * const grep_usage[] = {
  22         "git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]",
  23         NULL
  24 };
  25
  26 static int use_threads = 1;
  27
  28 #ifndef NO_PTHREADS
  29 #define THREADS 8
  30 static pthread_t threads[THREADS];
  31
  32 /* We use one producer thread and THREADS consumer
  33  * threads. The producer adds struct work_items to 'todo' and the
  34  * consumers pick work items from the same array.
  35  */
  36 struct work_item {
  37         struct grep_source source;
  38         char done;
  39         struct strbuf out;
  40 };
  41
  42 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  43  * that have been or are processed by a consumer thread. We haven't
  44  * written the result for these to stdout yet.
  45  *
  46  * The work_items in [todo_start, todo_end) are waiting to be picked
  47  * up by a consumer thread.
  48  *
  49  * The ranges are modulo TODO_SIZE.
  50  */
  51 #define TODO_SIZE 128
  52 static struct work_item todo[TODO_SIZE];
  53 static int todo_start;
  54 static int todo_end;
  55 static int todo_done;
  56
  57 /* Has all work items been added? */
  58 static int all_work_added;
  59
  60 /* This lock protects all the variables above. */
  61 static pthread_mutex_t grep_mutex;
  62
  63 static inline void grep_lock(void)
  64 {
  65         if (use_threads)
  66                 pthread_mutex_lock(&grep_mutex);
  67 }
  68
  69 static inline void grep_unlock(void)
  70 {
  71         if (use_threads)
  72                 pthread_mutex_unlock(&grep_mutex);
  73 }
  74
  75 /* Signalled when a new work_item is added to todo. */
  76 static pthread_cond_t cond_add;
  77
  78 /* Signalled when the result from one work_item is written to
  79  * stdout.
  80  */
  81 static pthread_cond_t cond_write;
  82
  83 /* Signalled when we are finished with everything. */
  84 static pthread_cond_t cond_result;
  85
  86 static int skip_first_line;
  87
  88 static void add_work(struct grep_opt *opt, enum grep_source_type type,
  89                      const char *name, const void *id)
  90 {
  91         grep_lock();
  92
  93         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  94                 pthread_cond_wait(&cond_write, &grep_mutex);
  95         }
  96
  97         grep_source_init(&todo[todo_end].source, type, name, id);
  98         if (opt->binary != GREP_BINARY_TEXT)
  99                 grep_source_load_driver(&todo[todo_end].source);
 100         todo[todo_end].done = 0;
 101         strbuf_reset(&todo[todo_end].out);
 102         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 103
 104         pthread_cond_signal(&cond_add);
 105         grep_unlock();
 106 }
 107
 108 static struct work_item *get_work(void)
 109 {
 110         struct work_item *ret;
 111
 112         grep_lock();
 113         while (todo_start == todo_end && !all_work_added) {
 114                 pthread_cond_wait(&cond_add, &grep_mutex);
 115         }
 116
 117         if (todo_start == todo_end && all_work_added) {
 118                 ret = NULL;
 119         } else {
 120                 ret = &todo[todo_start];
 121                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 122         }
 123         grep_unlock();
 124         return ret;
 125 }
 126
 127 static void work_done(struct work_item *w)
 128 {
 129         int old_done;
 130
 131         grep_lock();
 132         w->done = 1;
 133         old_done = todo_done;
 134         for(; todo[todo_done].done && todo_done != todo_start;
 135             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 136                 w = &todo[todo_done];
 137                 if (w->out.len) {
 138                         const char *p = w->out.buf;
 139                         size_t len = w->out.len;
 140
 141                         /* Skip the leading hunk mark of the first file. */
 142                         if (skip_first_line) {
 143                                 while (len) {
 144                                         len--;
 145                                         if (*p++ == '\n')
 146                                                 break;
 147                                 }
 148                                 skip_first_line = 0;
 149                         }
 150
 151                         write_or_die(1, p, len);
 152                 }
 153                 grep_source_clear(&w->source);
 154         }
 155
 156         if (old_done != todo_done)
 157                 pthread_cond_signal(&cond_write);
 158
 159         if (all_work_added && todo_done == todo_end)
 160                 pthread_cond_signal(&cond_result);
 161
 162         grep_unlock();
 163 }
 164
 165 static void *run(void *arg)
 166 {
 167         int hit = 0;
 168         struct grep_opt *opt = arg;
 169
 170         while (1) {
 171                 struct work_item *w = get_work();
 172                 if (!w)
 173                         break;
 174
 175                 opt->output_priv = w;
 176                 hit |= grep_source(opt, &w->source);
 177                 grep_source_clear_data(&w->source);
 178                 work_done(w);
 179         }
 180         free_grep_patterns(arg);
 181         free(arg);
 182
 183         return (void*) (intptr_t) hit;
 184 }
 185
 186 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 187 {
 188         struct work_item *w = opt->output_priv;
 189         strbuf_add(&w->out, buf, size);
 190 }
 191
 192 static void start_threads(struct grep_opt *opt)
 193 {
 194         int i;
 195
 196         pthread_mutex_init(&grep_mutex, NULL);
 197         pthread_mutex_init(&grep_read_mutex, NULL);
 198         pthread_mutex_init(&grep_attr_mutex, NULL);
 199         pthread_cond_init(&cond_add, NULL);
 200         pthread_cond_init(&cond_write, NULL);
 201         pthread_cond_init(&cond_result, NULL);
 202         grep_use_locks = 1;
 203
 204         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 205                 strbuf_init(&todo[i].out, 0);
 206         }
 207
 208         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 209                 int err;
 210                 struct grep_opt *o = grep_opt_dup(opt);
 211                 o->output = strbuf_out;
 212                 compile_grep_patterns(o);
 213                 err = pthread_create(&threads[i], NULL, run, o);
 214
 215                 if (err)
 216                         die(_("grep: failed to create thread: %s"),
 217                             strerror(err));
 218         }
 219 }
 220
 221 static int wait_all(void)
 222 {
 223         int hit = 0;
 224         int i;
 225
 226         grep_lock();
 227         all_work_added = 1;
 228
 229         /* Wait until all work is done. */
 230         while (todo_done != todo_end)
 231                 pthread_cond_wait(&cond_result, &grep_mutex);
 232
 233         /* Wake up all the consumer threads so they can see that there
 234          * is no more work to do.
 235          */
 236         pthread_cond_broadcast(&cond_add);
 237         grep_unlock();
 238
 239         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 240                 void *h;
 241                 pthread_join(threads[i], &h);
 242                 hit |= (int) (intptr_t) h;
 243         }
 244
 245         pthread_mutex_destroy(&grep_mutex);
 246         pthread_mutex_destroy(&grep_read_mutex);
 247         pthread_mutex_destroy(&grep_attr_mutex);
 248         pthread_cond_destroy(&cond_add);
 249         pthread_cond_destroy(&cond_write);
 250         pthread_cond_destroy(&cond_result);
 251         grep_use_locks = 0;
 252
 253         return hit;
 254 }
 255 #else /* !NO_PTHREADS */
 256
 257 static int wait_all(void)
 258 {
 259         return 0;
 260 }
 261 #endif
 262
 263 static int grep_config(const char *var, const char *value, void *cb)
 264 {
 265         struct grep_opt *opt = cb;
 266         char *color = NULL;
 267
 268         if (userdiff_config(var, value) < 0)
 269                 return -1;
 270
 271         if (!strcmp(var, "grep.extendedregexp")) {
 272                 if (git_config_bool(var, value))
 273                         opt->regflags |= REG_EXTENDED;
 274                 else
 275                         opt->regflags &= ~REG_EXTENDED;
 276                 return 0;
 277         }
 278
 279         if (!strcmp(var, "grep.linenumber")) {
 280                 opt->linenum = git_config_bool(var, value);
 281                 return 0;
 282         }
 283
 284         if (!strcmp(var, "color.grep"))
 285                 opt->color = git_config_colorbool(var, value);
 286         else if (!strcmp(var, "color.grep.context"))
 287                 color = opt->color_context;
 288         else if (!strcmp(var, "color.grep.filename"))
 289                 color = opt->color_filename;
 290         else if (!strcmp(var, "color.grep.function"))
 291                 color = opt->color_function;
 292         else if (!strcmp(var, "color.grep.linenumber"))
 293                 color = opt->color_lineno;
 294         else if (!strcmp(var, "color.grep.match"))
 295                 color = opt->color_match;
 296         else if (!strcmp(var, "color.grep.selected"))
 297                 color = opt->color_selected;
 298         else if (!strcmp(var, "color.grep.separator"))
 299                 color = opt->color_sep;
 300         else
 301                 return git_color_default_config(var, value, cb);
 302         if (color) {
 303                 if (!value)
 304                         return config_error_nonbool(var);
 305                 color_parse(value, var, color);
 306         }
 307         return 0;
 308 }
 309
 310 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 311 {
 312         void *data;
 313
 314         grep_read_lock();
 315         data = read_sha1_file(sha1, type, size);
 316         grep_read_unlock();
 317         return data;
 318 }
 319
 320 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 321                      const char *filename, int tree_name_len)
 322 {
 323         struct strbuf pathbuf = STRBUF_INIT;
 324
 325         if (opt->relative && opt->prefix_length) {
 326                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 327                                     opt->prefix);
 328                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 329         } else {
 330                 strbuf_addstr(&pathbuf, filename);
 331         }
 332
 333 #ifndef NO_PTHREADS
 334         if (use_threads) {
 335                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 336                 strbuf_release(&pathbuf);
 337                 return 0;
 338         } else
 339 #endif
 340         {
 341                 struct grep_source gs;
 342                 int hit;
 343
 344                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 345                 strbuf_release(&pathbuf);
 346                 hit = grep_source(opt, &gs);
 347
 348                 grep_source_clear(&gs);
 349                 return hit;
 350         }
 351 }
 352
 353 static int grep_file(struct grep_opt *opt, const char *filename)
 354 {
 355         struct strbuf buf = STRBUF_INIT;
 356
 357         if (opt->relative && opt->prefix_length)
 358                 quote_path_relative(filename, -1, &buf, opt->prefix);
 359         else
 360                 strbuf_addstr(&buf, filename);
 361
 362 #ifndef NO_PTHREADS
 363         if (use_threads) {
 364                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
 365                 strbuf_release(&buf);
 366                 return 0;
 367         } else
 368 #endif
 369         {
 370                 struct grep_source gs;
 371                 int hit;
 372
 373                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
 374                 strbuf_release(&buf);
 375                 hit = grep_source(opt, &gs);
 376
 377                 grep_source_clear(&gs);
 378                 return hit;
 379         }
 380 }
 381
 382 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 383 {
 384         struct string_list *path_list = opt->output_priv;
 385
 386         if (len == 1 && *(const char *)data == '\0')
 387                 return;
 388         string_list_append(path_list, xstrndup(data, len));
 389 }
 390
 391 static void run_pager(struct grep_opt *opt, const char *prefix)
 392 {
 393         struct string_list *path_list = opt->output_priv;
 394         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 395         int i, status;
 396
 397         for (i = 0; i < path_list->nr; i++)
 398                 argv[i] = path_list->items[i].string;
 399         argv[path_list->nr] = NULL;
 400
 401         if (prefix && chdir(prefix))
 402                 die(_("Failed to chdir: %s"), prefix);
 403         status = run_command_v_opt(argv, RUN_USING_SHELL);
 404         if (status)
 405                 exit(status);
 406         free(argv);
 407 }
 408
 409 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 410 {
 411         int hit = 0;
 412         int nr;
 413         read_cache();
 414
 415         for (nr = 0; nr < active_nr; nr++) {
 416                 struct cache_entry *ce = active_cache[nr];
 417                 if (!S_ISREG(ce->ce_mode))
 418                         continue;
 419                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 420                         continue;
 421                 /*
 422                  * If CE_VALID is on, we assume worktree file and its cache entry
 423                  * are identical, even if worktree file has been modified, so use
 424                  * cache version instead
 425                  */
 426                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 427                         if (ce_stage(ce))
 428                                 continue;
 429                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 430                 }
 431                 else
 432                         hit |= grep_file(opt, ce->name);
 433                 if (ce_stage(ce)) {
 434                         do {
 435                                 nr++;
 436                         } while (nr < active_nr &&
 437                                  !strcmp(ce->name, active_cache[nr]->name));
 438                         nr--; /* compensate for loop control */
 439                 }
 440                 if (hit && opt->status_only)
 441                         break;
 442         }
 443         return hit;
 444 }
 445
 446 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 447                      struct tree_desc *tree, struct strbuf *base, int tn_len)
 448 {
 449         int hit = 0;
 450         enum interesting match = entry_not_interesting;
 451         struct name_entry entry;
 452         int old_baselen = base->len;
 453
 454         while (tree_entry(tree, &entry)) {
 455                 int te_len = tree_entry_len(&entry);
 456
 457                 if (match != all_entries_interesting) {
 458                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 459                         if (match == all_entries_not_interesting)
 460                                 break;
 461                         if (match == entry_not_interesting)
 462                                 continue;
 463                 }
 464
 465                 strbuf_add(base, entry.path, te_len);
 466
 467                 if (S_ISREG(entry.mode)) {
 468                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 469                 }
 470                 else if (S_ISDIR(entry.mode)) {
 471                         enum object_type type;
 472                         struct tree_desc sub;
 473                         void *data;
 474                         unsigned long size;
 475
 476                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 477                         if (!data)
 478                                 die(_("unable to read tree (%s)"),
 479                                     sha1_to_hex(entry.sha1));
 480
 481                         strbuf_addch(base, '/');
 482                         init_tree_desc(&sub, data, size);
 483                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 484                         free(data);
 485                 }
 486                 strbuf_setlen(base, old_baselen);
 487
 488                 if (hit && opt->status_only)
 489                         break;
 490         }
 491         return hit;
 492 }
 493
 494 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 495                        struct object *obj, const char *name)
 496 {
 497         if (obj->type == OBJ_BLOB)
 498                 return grep_sha1(opt, obj->sha1, name, 0);
 499         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 500                 struct tree_desc tree;
 501                 void *data;
 502                 unsigned long size;
 503                 struct strbuf base;
 504                 int hit, len;
 505
 506                 grep_read_lock();
 507                 data = read_object_with_reference(obj->sha1, tree_type,
 508                                                   &size, NULL);
 509                 grep_read_unlock();
 510
 511                 if (!data)
 512                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 513
 514                 len = name ? strlen(name) : 0;
 515                 strbuf_init(&base, PATH_MAX + len + 1);
 516                 if (len) {
 517                         strbuf_add(&base, name, len);
 518                         strbuf_addch(&base, ':');
 519                 }
 520                 init_tree_desc(&tree, data, size);
 521                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 522                 strbuf_release(&base);
 523                 free(data);
 524                 return hit;
 525         }
 526         die(_("unable to grep from object of type %s"), typename(obj->type));
 527 }
 528
 529 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 530                         const struct object_array *list)
 531 {
 532         unsigned int i;
 533         int hit = 0;
 534         const unsigned int nr = list->nr;
 535
 536         for (i = 0; i < nr; i++) {
 537                 struct object *real_obj;
 538                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 539                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 540                         hit = 1;
 541                         if (opt->status_only)
 542                                 break;
 543                 }
 544         }
 545         return hit;
 546 }
 547
 548 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 549                           int exc_std)
 550 {
 551         struct dir_struct dir;
 552         int i, hit = 0;
 553
 554         memset(&dir, 0, sizeof(dir));
 555         if (exc_std)
 556                 setup_standard_excludes(&dir);
 557
 558         fill_directory(&dir, pathspec->raw);
 559         for (i = 0; i < dir.nr; i++) {
 560                 const char *name = dir.entries[i]->name;
 561                 int namelen = strlen(name);
 562                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 563                         continue;
 564                 hit |= grep_file(opt, dir.entries[i]->name);
 565                 if (hit && opt->status_only)
 566                         break;
 567         }
 568         return hit;
 569 }
 570
 571 static int context_callback(const struct option *opt, const char *arg,
 572                             int unset)
 573 {
 574         struct grep_opt *grep_opt = opt->value;
 575         int value;
 576         const char *endp;
 577
 578         if (unset) {
 579                 grep_opt->pre_context = grep_opt->post_context = 0;
 580                 return 0;
 581         }
 582         value = strtol(arg, (char **)&endp, 10);
 583         if (*endp) {
 584                 return error(_("switch `%c' expects a numerical value"),
 585                              opt->short_name);
 586         }
 587         grep_opt->pre_context = grep_opt->post_context = value;
 588         return 0;
 589 }
 590
 591 static int file_callback(const struct option *opt, const char *arg, int unset)
 592 {
 593         struct grep_opt *grep_opt = opt->value;
 594         int from_stdin = !strcmp(arg, "-");
 595         FILE *patterns;
 596         int lno = 0;
 597         struct strbuf sb = STRBUF_INIT;
 598
 599         patterns = from_stdin ? stdin : fopen(arg, "r");
 600         if (!patterns)
 601                 die_errno(_("cannot open '%s'"), arg);
 602         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 603                 char *s;
 604                 size_t len;
 605
 606                 /* ignore empty line like grep does */
 607                 if (sb.len == 0)
 608                         continue;
 609
 610                 s = strbuf_detach(&sb, &len);
 611                 append_grep_pat(grep_opt, s, len, arg, ++lno, GREP_PATTERN);
 612         }
 613         if (!from_stdin)
 614                 fclose(patterns);
 615         strbuf_release(&sb);
 616         return 0;
 617 }
 618
 619 static int not_callback(const struct option *opt, const char *arg, int unset)
 620 {
 621         struct grep_opt *grep_opt = opt->value;
 622         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 623         return 0;
 624 }
 625
 626 static int and_callback(const struct option *opt, const char *arg, int unset)
 627 {
 628         struct grep_opt *grep_opt = opt->value;
 629         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 630         return 0;
 631 }
 632
 633 static int open_callback(const struct option *opt, const char *arg, int unset)
 634 {
 635         struct grep_opt *grep_opt = opt->value;
 636         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 637         return 0;
 638 }
 639
 640 static int close_callback(const struct option *opt, const char *arg, int unset)
 641 {
 642         struct grep_opt *grep_opt = opt->value;
 643         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 644         return 0;
 645 }
 646
 647 static int pattern_callback(const struct option *opt, const char *arg,
 648                             int unset)
 649 {
 650         struct grep_opt *grep_opt = opt->value;
 651         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 652         return 0;
 653 }
 654
 655 static int help_callback(const struct option *opt, const char *arg, int unset)
 656 {
 657         return -1;
 658 }
 659
 660 int cmd_grep(int argc, const char **argv, const char *prefix)
 661 {
 662         int hit = 0;
 663         int cached = 0, untracked = 0, opt_exclude = -1;
 664         int seen_dashdash = 0;
 665         int external_grep_allowed__ignored;
 666         const char *show_in_pager = NULL, *default_pager = "dummy";
 667         struct grep_opt opt;
 668         struct object_array list = OBJECT_ARRAY_INIT;
 669         const char **paths = NULL;
 670         struct pathspec pathspec;
 671         struct string_list path_list = STRING_LIST_INIT_NODUP;
 672         int i;
 673         int dummy;
 674         int use_index = 1;
 675         enum {
 676                 pattern_type_unspecified = 0,
 677                 pattern_type_bre,
 678                 pattern_type_ere,
 679                 pattern_type_fixed,
 680                 pattern_type_pcre,
 681         };
 682         int pattern_type = pattern_type_unspecified;
 683
 684         struct option options[] = {
 685                 OPT_BOOLEAN(0, "cached", &cached,
 686                         "search in index instead of in the work tree"),
 687                 OPT_NEGBIT(0, "no-index", &use_index,
 688                          "finds in contents not managed by git", 1),
 689                 OPT_BOOLEAN(0, "untracked", &untracked,
 690                         "search in both tracked and untracked files"),
 691                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 692                             "search also in ignored files", 1),
 693                 OPT_GROUP(""),
 694                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 695                         "show non-matching lines"),
 696                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 697                         "case insensitive matching"),
 698                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 699                         "match patterns only at word boundaries"),
 700                 OPT_SET_INT('a', "text", &opt.binary,
 701                         "process binary files as text", GREP_BINARY_TEXT),
 702                 OPT_SET_INT('I', NULL, &opt.binary,
 703                         "don't match patterns in binary files",
 704                         GREP_BINARY_NOMATCH),
 705                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 706                         "descend at most <depth> levels", PARSE_OPT_NONEG,
 707                         NULL, 1 },
 708                 OPT_GROUP(""),
 709                 OPT_SET_INT('E', "extended-regexp", &pattern_type,
 710                             "use extended POSIX regular expressions",
 711                             pattern_type_ere),
 712                 OPT_SET_INT('G', "basic-regexp", &pattern_type,
 713                             "use basic POSIX regular expressions (default)",
 714                             pattern_type_bre),
 715                 OPT_SET_INT('F', "fixed-strings", &pattern_type,
 716                             "interpret patterns as fixed strings",
 717                             pattern_type_fixed),
 718                 OPT_SET_INT('P', "perl-regexp", &pattern_type,
 719                             "use Perl-compatible regular expressions",
 720                             pattern_type_pcre),
 721                 OPT_GROUP(""),
 722                 OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
 723                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 724                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 725                 OPT_NEGBIT(0, "full-name", &opt.relative,
 726                         "show filenames relative to top directory", 1),
 727                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 728                         "show only filenames instead of matching lines"),
 729                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 730                         "synonym for --files-with-matches"),
 731                 OPT_BOOLEAN('L', "files-without-match",
 732                         &opt.unmatch_name_only,
 733                         "show only the names of files without match"),
 734                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 735                         "print NUL after filenames"),
 736                 OPT_BOOLEAN('c', "count", &opt.count,
 737                         "show the number of matches instead of matching lines"),
 738                 OPT__COLOR(&opt.color, "highlight matches"),
 739                 OPT_BOOLEAN(0, "break", &opt.file_break,
 740                         "print empty line between matches from different files"),
 741                 OPT_BOOLEAN(0, "heading", &opt.heading,
 742                         "show filename only once above matches from same file"),
 743                 OPT_GROUP(""),
 744                 OPT_CALLBACK('C', "context", &opt, "n",
 745                         "show <n> context lines before and after matches",
 746                         context_callback),
 747                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 748                         "show <n> context lines before matches"),
 749                 OPT_INTEGER('A', "after-context", &opt.post_context,
 750                         "show <n> context lines after matches"),
 751                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 752                         context_callback),
 753                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 754                         "show a line with the function name before matches"),
 755                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 756                         "show the surrounding function"),
 757                 OPT_GROUP(""),
 758                 OPT_CALLBACK('f', NULL, &opt, "file",
 759                         "read patterns from file", file_callback),
 760                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 761                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 762                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 763                   "combine patterns specified with -e",
 764                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 765                 OPT_BOOLEAN(0, "or", &dummy, ""),
 766                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 767                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 768                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 769                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 770                   open_callback },
 771                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 772                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 773                   close_callback },
 774                 OPT__QUIET(&opt.status_only,
 775                            "indicate hit with exit status without output"),
 776                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 777                         "show only matches from files that match all patterns"),
 778                 OPT_GROUP(""),
 779                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 780                         "pager", "show matching files in the pager",
 781                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 782                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 783                             "allow calling of grep(1) (ignored by this build)"),
 784                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 785                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 786                 OPT_END()
 787         };
 788
 789         /*
 790          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 791          * to show usage information and exit.
 792          */
 793         if (argc == 2 && !strcmp(argv[1], "-h"))
 794                 usage_with_options(grep_usage, options);
 795
 796         memset(&opt, 0, sizeof(opt));
 797         opt.prefix = prefix;
 798         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 799         opt.relative = 1;
 800         opt.pathname = 1;
 801         opt.pattern_tail = &opt.pattern_list;
 802         opt.header_tail = &opt.header_list;
 803         opt.regflags = REG_NEWLINE;
 804         opt.max_depth = -1;
 805
 806         strcpy(opt.color_context, "");
 807         strcpy(opt.color_filename, "");
 808         strcpy(opt.color_function, "");
 809         strcpy(opt.color_lineno, "");
 810         strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
 811         strcpy(opt.color_selected, "");
 812         strcpy(opt.color_sep, GIT_COLOR_CYAN);
 813         opt.color = -1;
 814         git_config(grep_config, &opt);
 815
 816         /*
 817          * If there is no -- then the paths must exist in the working
 818          * tree.  If there is no explicit pattern specified with -e or
 819          * -f, we take the first unrecognized non option to be the
 820          * pattern, but then what follows it must be zero or more
 821          * valid refs up to the -- (if exists), and then existing
 822          * paths.  If there is an explicit pattern, then the first
 823          * unrecognized non option is the beginning of the refs list
 824          * that continues up to the -- (if exists), and then paths.
 825          */
 826         argc = parse_options(argc, argv, prefix, options, grep_usage,
 827                              PARSE_OPT_KEEP_DASHDASH |
 828                              PARSE_OPT_STOP_AT_NON_OPTION |
 829                              PARSE_OPT_NO_INTERNAL_HELP);
 830         switch (pattern_type) {
 831         case pattern_type_fixed:
 832                 opt.fixed = 1;
 833                 opt.pcre = 0;
 834                 break;
 835         case pattern_type_bre:
 836                 opt.fixed = 0;
 837                 opt.pcre = 0;
 838                 opt.regflags &= ~REG_EXTENDED;
 839                 break;
 840         case pattern_type_ere:
 841                 opt.fixed = 0;
 842                 opt.pcre = 0;
 843                 opt.regflags |= REG_EXTENDED;
 844                 break;
 845         case pattern_type_pcre:
 846                 opt.fixed = 0;
 847                 opt.pcre = 1;
 848                 break;
 849         default:
 850                 break; /* nothing */
 851         }
 852
 853         if (use_index && !startup_info->have_repository)
 854                 /* die the same way as if we did it at the beginning */
 855                 setup_git_directory();
 856
 857         /*
 858          * skip a -- separator; we know it cannot be
 859          * separating revisions from pathnames if
 860          * we haven't even had any patterns yet
 861          */
 862         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 863                 argv++;
 864                 argc--;
 865         }
 866
 867         /* First unrecognized non-option token */
 868         if (argc > 0 && !opt.pattern_list) {
 869                 append_grep_pattern(&opt, argv[0], "command line", 0,
 870                                     GREP_PATTERN);
 871                 argv++;
 872                 argc--;
 873         }
 874
 875         if (show_in_pager == default_pager)
 876                 show_in_pager = git_pager(1);
 877         if (show_in_pager) {
 878                 opt.color = 0;
 879                 opt.name_only = 1;
 880                 opt.null_following_name = 1;
 881                 opt.output_priv = &path_list;
 882                 opt.output = append_path;
 883                 string_list_append(&path_list, show_in_pager);
 884                 use_threads = 0;
 885         }
 886
 887         if (!opt.pattern_list)
 888                 die(_("no pattern given."));
 889         if (!opt.fixed && opt.ignore_case)
 890                 opt.regflags |= REG_ICASE;
 891
 892         compile_grep_patterns(&opt);
 893
 894         /* Check revs and then paths */
 895         for (i = 0; i < argc; i++) {
 896                 const char *arg = argv[i];
 897                 unsigned char sha1[20];
 898                 /* Is it a rev? */
 899                 if (!get_sha1(arg, sha1)) {
 900                         struct object *object = parse_object(sha1);
 901                         if (!object)
 902                                 die(_("bad object %s"), arg);
 903                         add_object_array(object, arg, &list);
 904                         continue;
 905                 }
 906                 if (!strcmp(arg, "--")) {
 907                         i++;
 908                         seen_dashdash = 1;
 909                 }
 910                 break;
 911         }
 912
 913 #ifndef NO_PTHREADS
 914         if (list.nr || cached || online_cpus() == 1)
 915                 use_threads = 0;
 916 #else
 917         use_threads = 0;
 918 #endif
 919
 920 #ifndef NO_PTHREADS
 921         if (use_threads) {
 922                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 923                     && (opt.pre_context || opt.post_context ||
 924                         opt.file_break || opt.funcbody))
 925                         skip_first_line = 1;
 926                 start_threads(&opt);
 927         }
 928 #endif
 929
 930         /* The rest are paths */
 931         if (!seen_dashdash) {
 932                 int j;
 933                 for (j = i; j < argc; j++)
 934                         verify_filename(prefix, argv[j]);
 935         }
 936
 937         paths = get_pathspec(prefix, argv + i);
 938         init_pathspec(&pathspec, paths);
 939         pathspec.max_depth = opt.max_depth;
 940         pathspec.recursive = 1;
 941
 942         if (show_in_pager && (cached || list.nr))
 943                 die(_("--open-files-in-pager only works on the worktree"));
 944
 945         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 946                 const char *pager = path_list.items[0].string;
 947                 int len = strlen(pager);
 948
 949                 if (len > 4 && is_dir_sep(pager[len - 5]))
 950                         pager += len - 4;
 951
 952                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 953                         struct strbuf buf = STRBUF_INIT;
 954                         strbuf_addf(&buf, "+/%s%s",
 955                                         strcmp("less", pager) ? "" : "*",
 956                                         opt.pattern_list->pattern);
 957                         string_list_append(&path_list, buf.buf);
 958                         strbuf_detach(&buf, NULL);
 959                 }
 960         }
 961
 962         if (!show_in_pager)
 963                 setup_pager();
 964
 965         if (!use_index && (untracked || cached))
 966                 die(_("--cached or --untracked cannot be used with --no-index."));
 967
 968         if (!use_index || untracked) {
 969                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 970                 if (list.nr)
 971                         die(_("--no-index or --untracked cannot be used with revs."));
 972                 hit = grep_directory(&opt, &pathspec, use_exclude);
 973         } else if (0 <= opt_exclude) {
 974                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 975         } else if (!list.nr) {
 976                 if (!cached)
 977                         setup_work_tree();
 978
 979                 hit = grep_cache(&opt, &pathspec, cached);
 980         } else {
 981                 if (cached)
 982                         die(_("both --cached and trees are given."));
 983                 hit = grep_objects(&opt, &pathspec, &list);
 984         }
 985
 986         if (use_threads)
 987                 hit |= wait_all();
 988         if (hit && show_in_pager)
 989                 run_pager(&opt, prefix);
 990         free_grep_patterns(&opt);
 991         return !hit;
 992 }